Question

once heterochromatin has been established, it will often spread until it encounters which of the following?

Answer 1

Once heterochromatin has been established, it will often spread until it encounters (A) a barrier DNA sequence. So option (A) is the correct answer.

The shape of chromatin in which sections of interphase chromosomes reside is highly dependent on histone tail modifications. When heterochromatin-specific proteins bind to chromosomes, they also tend to modify the tails of adjacent nucleosomes, causing heterochromatin spreading. This diffusion continues until the remodeling protein reaches a DNA sequence that acts as a barrier. Barrier sequences function by having another histone modification that favors the euchromatin conformation. For example, a common barrier DNA sequence modification is to add an acetyl group to lysine 9 of histone H3. This blocks heterochromatin-induced alteration of methylation at the same lysine residue of histone H3.

Complete question:

Once heterochromatin has been established, it will often spread until it encounters which of the following?

A. a barrier DNA sequence

B. euchromatin

C. histone H3 methylated on lysine 9

D. a nucleosome

E. a gene

Learn more about DNA sequence from:

https://brainly.com/question/23310851

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